1. Field of the Invention
The present invention relates to a window shade lift cord apparatus and particularly to a lift cord apparatus for retracting a window shade.
2. Brief Discussion of the Related Art
Conventional window coverings such as shade, blinds, and the like mainly aim to block external light from entering indoors, and serve ornamental purpose. Refer to FIG. 1 for the structure of a window covering 10 proposed by the Applicant in U.S. Pat. No. 6,443,207. It mainly includes an upper track 11, a lower track 12, a foldable pleat 13, two cords 14 and 15, and two adjustment switches 16 and 17. The pleat 13 is located between the upper track 11 and the lower track 12. The two cords 14 and 15 oppose each other and tread through the pleat 13. The two adjustment switches 16 and 17 are located beneath the lower track 12 to control the movement of the two cords 14 and 15.
When in use to retract the pleat 13 of the window covering 10, a user has first to control the adjustment switches 16 and 17 to make the cords 14 and 15 in a movable condition. Then pull the cords 14 and 15 downwards to lift the pleat 13 upwards for retraction. To lower the pleat 13, also control the two adjustment switches 16 and 17 to make the cords 14 and 15 in a movable condition, then the pleat 13 drops automatically because of gravity force for extension. Thereby the window covering 10 can be retracted and extended as desired.
However, during retracting operation of the window covering 10, the two adjustment switches 16 and 17 have to be controlled, and the two cords 14 and 15 have to be pulled downwards. Hence the user has to use one hand to control the adjustment switch 16 on one side and another hand to pull the cord 14 to retract one side of the window covering 10 upwards to a selected elevation, then to control another adjustment switch 17 with one hand on another side and pull another cord 15 with another hand to retract another side of the window covering 10 to the selected elevation. In other words, the operations have to be done repeatedly and alternately on two sides to lift the pleat 13 and retract the window covering 10 to the desired elevation. It is a tedious process.